Cars' disappearance leaves owners searching for answers.

The Tesla Model S is not an easy car to steal, as it features a GPS tracking system that is permanently activated. And it’s incredibly effective.

Last year, a thief in Vancouver discovered as much to his cost when the owner of a Model S he had stolen was able to follow real-time updates on the car’s location via the Tesla app and direct police to intercept him.

But two Model S owners in Germany are now searching for answers after their cars were stolen and disappeared without trace, reports Electrek.

Unlike the Vancouver incident, both cars were stolen without the key. One was taken in Dusseldorf in June, the other - a brand-new car - from nearby Essen in August. Both were P90D models.

According to the owner of the second car, neither the police nor Tesla have found any trace of it.

A thread on the German Tesla Owners Club forum has produced a leading theory as to how the thief or thieves were able to circumvent the tracker: that the owners’ Tesla accounts were hacked - one admitted to using a weak password - and then the thief managed to either block the GPS signal or remove the sim card.

Add breaking into the car without the key, and these were clearly difficult, technologically sophisticated crimes. Tesla hasn’t commented on the theories.

Sadly, it seems likely the stolen cars are long gone. Of more concern is whether or not there is a real, exploitable weakness in Tesla’s security systems.